Electric circuit breakers



Nov. 3, 1959 E. COLEMAN ELECTRIC CIRCUIT BREAKERS Filed April 18, 1956F/ G. /a /3 U x4 I" WW" w P 2? I I l:

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ELECTRIC CIRCUIT BREAKERS Filed April 18, 1956 2 Sheets-Sheet 2 InventorA [torn e y United States Patent ELECTRIC CIRCUIT BREAKERS EdwardColeman, Walsall, England, assignor to J. A. 'Crabtree & Co. Limited,Walsall, England, a British c mp ny Application April '18, 1956, SerialNo. 579,020 .Claims priority, application Great Britain June 17, 1955Claims. (CL 200-94) This invention relates to electric circuit breakersand 1 is-particularly concerned with lever-operated arrangements avoidsthe necessity for employing a dummy cover for holding the parts inposition during this factory operation.

Another important feature of the invention resides insecuring one of theplates to the casing in the plane of the lever pivot. Disposing securingmeans in this plane excludes any possibility of the riveted inner unitinadvertentlyllfting away from the fixed contacts.

A further feature of the instant invention encompasses the use of flatplates adapted to be stamped out of a thin metal strip, thus eliminatingundue wastage of material. The flat strip can then be accurately drilledfor both pivot and rivet holes by a single tool at one operation foreconomical mass production.

In order to enable the invention to be readily understood reference willnow be made to the accompanying drawings illustrating by way of exampledifferent constructions for carrying the invention into effect, in whichdrawings:

Figure 1 is a side elevation with parts in section of a double-poleearth leakage circuit breaker.

Figure 2 is a section on the line II-II of Figure 1.

Figure 3 is a perspective view of the lever, and an associated set ofparts for one pole of the double-pole construction, such parts beingdisassembled from one another.

Figure 4 is a perspective view of one of the plates for a single poleconstruction.

Referring to Figures 1 to 3 of the drawings a pair of parallel metalplates 1-arc disposed on the inner faces of the side walls 2 of themoulded casing 3. Each plate is formed with a bent foot 1" having atapped opening into which is entered a screw 4 introduced through acountersunk opening in the base of the moulded casing. Each of a pair ofshorter parallel plates 5, disposed between the plates 1, is connectedto one of the latter by a right-angled frame 6 secured by a screw 7 tothe base. Short rectangular projections 8 on the sides of the frame areentered into similarly shaped openings 9 in each pair of plates 1 and 5,and are riveted over in an assembly jig. Another pair of slightly longerprojections 8 on the frame are employed for location in the mouldedcasing, one of these projections extending through an opening 9 in theplate 1, into a groove 10 in a side wall of the casing, while the otherprojection is disposed in a groove 11 in a central partition 12.

The plates 1 are formed with circular holes for the reception of pinsadapted for the mounting of different parts. Thus the pivot pin 13 forthe lever 14 is mounted in openings 15 at the upper ends of the plate 1,the outer ends of pins 13 extending into guiding grooves 16 in themoulded cover 17, see Fig. 2. A short inwardly extending rivet 18 oneach plate 1 acts as a stop for one arm of a lever spring (not shown).Each plate 1 is also formed with acircular hole 19" for receiving thereduced end of a pivot pin 19 on which an armature 20 is pivotallymounted. This end is riveted over for rigidly securing the pin 19 inposition within the hole 19 and serves also for securing a stop member21 having an extension 21 overhanging the armature for limiting thespring urged movement of the armature away from its magnet 22. The stop21 is also formed with a rectangular opening 21 through which extends aprojection 8. A spring 23 is coiled around the pin 19 and has an endengaging a depending trip leg 20* of the armature. The free end of thespring legs being adapted to produce tripping by impinging on atransverse pin 30, see Fig. l.

The operation of this device is similar to that described and disclosedin various patents to Wilckens, for example in Nos. 2,689,282;2,690,486; and 2,781,433.

Pins 24 and 28 are received in holes 26 and 29 respectively in the lowerends of the plates 1 and 5. Each pin 24 serves for centering theconvolutions 25 of a spring the ends 25 of which bear on the frame 6,while the loop 25 acts on a moving contact 27 for urging it intopressure engagement with a fixed contact 31. Each moving contact 27 isformed with a short elongated slot 27 through which extends the pin 28,so that itlis guided for pivotal movement to a restricted extent over.suchpin, this arrangement constituting the moving contact hinge orpivot.

For the single pole construction a lever actuates a single set of partsand the frame 6 is riveted to a plate 1 and to a plate 32, Figure 4,which is provided instead of the plate 5. The holes 33 and 34 in theplate 32 receive respectively the pins 13 and 19, the remaining holestherein corresponding to the similarly numbered openings in the plate 5,as shown in Figure 3.

The forms of the invention here described and illustrated are presentedmerely as examples of how the invention may be embodied and applied.Other forms, embodiments and applications of the invention, comingwithin the proper scope of the appended claims, will, of course, suggestthemselves to those skilled in the art.

I claim:

1. In an electric circuit breaker having an insulated base, a fixedcontact, a moving contact, a lever operating said moving contact, atoggle disposed between said lever and said moving contact, anelectromagnet provided armature for tripping said toggle on overload, aframe having a right-angled foot for securement to said base, said frameprovided with spaced projections thereon, pins disposed therein forpivotally mounting said lever, armature and moving contact; parallelplates lying entirely within one plane, said plates provided withperforations disposed in mutually spaced relationship thereinconstructed and arranged to mount said pins and receive said projectionsin registered alignment therewith, means for securing said frame and atleast one of said plates in such mutually spaced alignment to said base,said aligned perforations serving to maintain said pivotal lever,armature and moving contact in operative registration.

2. In an electric circuit breaker having an insulated base, a fixedcontact, a moving contact, a lever operating said moving contact, atoggle disposed between said lever and said moving contact, anelectromagnet provided armature for tripping said toggle on overload, aframe provided with spaced rectangular projections thereon, pinsdisposed therein for pivotally mounting said lever, armature and movingcontact; parallel plates lying entirely within one plane, said platesprovided with perforations disposed in mutually spaced relationshiptherein constructed and arranged to mount said pins and matingly engagesaid rectangular projections in registered alignment therewith, meansfor securing said frame and at least one of said plates in such mutuallyspaced alignment to said base, said aligned perforations serving tomaintain said pivotal lever, armature and moving contact in operativeregistration. 1

3. In an electric circuit breaker having an insulated base, a fixedcontact, a moving contact, a lever operating least one of said plates insuch mutually spaced alignment to said base, said aligned perforationsserving to maintain said pivotal lever, armature and moving contact inoperative registration, wherein one of said plates engaging said frameis constructed and arranged to pivotally support said lever, armature,contact hinge'and main spring.

4. An electric circuit breaker comprising an insulated base, a cover, afixed contact, a moving contact, a lever operating said moving contact,a toggle disposed between said lever and said moving contact, anelectromagnet provided armature for tripping said toggle on overload,pins for pivotally mounting said lever, armature and moving contact, aframe provided with spaced projections thereon, parallel plates lyingentirely within one plane, said plates provided with perforationsdisposed in mutually spaced relationship therein constructed andarranged to mount said pins and receive said projections in registeredalignment therewith, means for securing said frame to said base, one ofsaid plates being secured to'said base in the pivotal plane of saidlever serving to prevent separation from said fixed contact upon removalof said cover for calibration purposes, wherein said alignedperforations maintain said pivotal lever, armature and moving contact inoperative registration.

5. An electric circuit breaker comprising" an insulated base, a fixedcontact, a moving contact, a lever operating said moving contact, atoggle disposed between said lever and said moving contact, anelectromagnet provided armature for tripping said toggle on overload,pins for pivotally mounting said lever, armature and moving contact, aframe provided with spaced projections thereon, onerof said projectionsextending for registered engagement with said base, parallel plateslying entirely :within one plane, said plates provided with perforationsdisposed in mutually spaced relationship therein constructed andarranged to mount said pins and receive said projections in registeredalignment therewith, means for securing said frame and at least one ofsaid plates in such mutually spaced alignment to said base, said alignedperforations serving to maintain said pivotal lever, armature and movingcontact in operative registration.

References Cited in the file of this patent" UNITED STATES PATENTSWilckens a Feb. 1957

